Decorating hydroxyapatite biomaterials with modular biologically active molecules

Abstract

A modular peptide design strategy wherein the modular peptide has two functional units separated by a spacer portion is disclosed. More particularly, the design strategy combines a hydroxyapatite-binding portion and a biomolecule-derived portion. The modular peptides have improved non-covalent binding to the surface of the HA-based materials, and are capable of initiating osteogenesis, angiogenesis, and/or osteogenic differentiation.

What is claimed is: 
     
       1. A modular peptide for non-covalently binding to a surface of a biomaterial, the modular peptide comprising: a hydroxyapatite-binding portion, a spacer portion, and a biomolecule-derived portion, wherein the hydroxyapatite-binding portion comprises an amino acid sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, and SEQ ID NO:6. 
     
     
       2. The modular peptide as set forth in  claim 1  wherein the biomaterial is selected from the group consisting of hydoxyapatite and hydroxyapatite-based materials. 
     
     
       3. The modular peptide as set forth in  claim 1  wherein the spacer portion is an amino acid sequence capable of forming an α-helix. 
     
     
       4. The modular peptide as set forth in  claim 1  wherein the spacer portion is SEQ ID NO:7. 
     
     
       5. The modular peptide as set forth in  claim 1  wherein the biomolecule-derived portion is a growth factor capable of initiating at least one of osteogenesis, angiogenesis, and osteogenic differentiation. 
     
     
       6. The modular peptide as set forth in  claim 5  wherein the growth factor comprises an amino acid sequence selected from the group consisting of SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, and SEQ ID NO:11. 
     
     
       7. The modular peptide as set forth in  claim 1  having the sequence selected from the group consisting of SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO: 14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, and SEQ ID NO:18.